Apparatus for producing voltage functions

ABSTRACT

An astable multivibrator applies periodically generated pulses to a frequency divider. The pulses from the frequency divider are decoded by a binary-to-decimal converter, and the outputs of the converter are applied to a plurality of potentiometers. The voltages from the movable contacts of the potentiometers are transmitted to a mixing amplifier which feeds an output amplifier. The output amplifier provides a signal to a deflection coil.

United States Patent 1 Thorn et al.

1 51 Aug. 14, 1973 1 APPARATUS FOR PRODUCING VOLTAGE FUNCTIONS [751 Inventors: Gernot Thorn, Hanau am Main;

Johann Sturmer, Freigericht, both of Germany [73] Assignee: Leybold-Heraeus-Verwaltung GmbH, Koln-Bayental, Germany [22] Filed: June 30, 1971 [21] Appl. No.: 158,262

[52] U.S. Cl 235/197, 328/14 [51] Int. Cl G06g 7/16 [58] Field 01 Search 235/197, 61 R, 61 A; 340/347 DA; 328/14, 27, 34, 39, 53, 142,

- [56] References Cited UNITED STATES PATENTS 3,540,037 11/1970 Ottesen 340/347 DA ASTABLE FREQUENCY m2 llULTll/IBRATOR [llVlDER 3,500,213 3/1970 Ameau 328/14 2,718,634 9/1955 Hansen 340/347 DA 2,970,306 l/1961 Zieman et al. 340/347 DA 3,040,221 6/1962 Fitzner 340/347 DA 3,486,018 12/1969 Warren 235/197 Primary ExaminerJoseph F. Ruggiero Attorney-Joseph F. Padlon 57 ABSTRACT An astable multivibrator applies periodically generated pulses to a frequency divider. The pulses from the frequency divider are decoded by a binary-to-decimal converter, and the outputs of the converter are applied to a plurality of potentiometers. The voltages from the movable contacts of the potentiometers are transmitted to a mixing amplifier which feeds an output amplifier. The output amplifier provides a signal to a deflection coil.

1 Claim, 2 Drawing Figures PATENTEDAUG 14 I975 SHEET 2 BF 2 APPARATUS FOR PRODUCING VOLTAGE FUNCTIONS BACKGROUND OF THE INVENTION The present invention relates to a method and arrangement for generating voltage functions which may be adjusted in curve configurations. In particular, the generated functions are intended for preset deflection functions for the deflection of an electron beam in a machining unit operating in conjunction with an elecheat may be generated at the edges of the machined 20 area.

For the evaporation of insulating materials, such as glass, quartz and the like, a 50 Hz deflection in the voltage curve of the line frequency is similarly ruled out. This is because the required focal spot does not develop due to the high orbit velocity of the beam.

The present invention progresses from the problem of indicating a method for the production of voltage functions that are adjustable to conform to curve configurations. In the present invention, a programmed 30 voltage generator furnishes per period or per cycle, a plurality of rectangular pulses of constant magnitude, in succession. The resulting pulses are attenuated through potentiometers assigned to each pulse, between proportions of and 100 percent. The sum of the attenuated pulses provides a signal that corresponds functionally to a predetermined curve. The form of the curve is determined by the potentiometer settings. With such a method, therefore, it is possible to obtain almost any desired function or curve, in a particularly simple manner. g

In the application of evaporating materials through an electron beam, it is desirable to use low frequency.

For this purpose, a low-ohmic output transistor circuit may be selected. Since all couplings are galvanic, furthermore, a direct current component can be additionally transmitted. This makes possiblebasic displacement of the beam for adjustment purposes. The specific and predetermined deflection function is taken from a specifically programmed voltage generator, as already described. The programmed, voltage generator may be advantageously constructed in the form of an astable multivibrator with output applied to a binary-todecimal decoder or converter, by way of a frequency divider. Potentiometer windings are connected to the outputs of the decoder, and the. movable contact settings of the potentiometers determine the attenuation and hence the voltage functions.

It may also be advantageous to apply the outputs of the potentiometers to an amplitude adjustment potentiometer, via a mixing amplifier. This amplitude adjustment potentiometer may be used to adjust the amplitude of the voltage function.

In one preferred embodiment used in practice, the programmed voltage generator provides rectangular pulses in succession. A four-stage frequency divider with dividing ratio of 2: l is connected to the pulse generator. A decoder with eight inputs and 16 outputs is, in turn, connected to the output of the frequency divider. Each of the 16 outputs is applied to a potentiometer. The signal outputs of the potentiometers are combined through a summing resistor network and applied to a mixing amplifier. An amplitude adjustment potentiometer is connected to the output circuit of the mixing amplifier. The settings of the 16 potentiometers at the outputs of the decoder, determine the form of the voltage function.

A particularly advantageous embodiment of the pres ent invention is obtained when the potentiometers are designed in the form of linear sliding potentiometers. The sliding parts of the potentiometers are movable within slide slots on the front panel of the apparatus. The sliding parts and hence the potentiometer settings are consequently positioned to correspond to the form of the desired curve. The corresponding voltage function is thereby obtained from the potentiometer settings. In the front panel of the device or apparatus, a number of such parallel slide slots are provided in correspondence to the desired resolution or subdivision. The movable contacts of the potentiometers slide within these slots. The positions of these movable contacts, in turn, determine the predetermined voltage function.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a circuit diagram for generating the voltage function, in accordance with the present invention;

FIG. 2 is a perspective view and shows the front panel of the apparatus of FIG. 1 with the adjusting elements of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, and in particular to FIG. 1, there is shown therein an astable multivibrator 1 which 0 has an output of successivepulses. These pulses are applied to a four-stage frequency divider 2 having a dividing ratio of 2:1 in each stage.

The output of the frequency divider 2 is applied to a decoder 3 of the binary to decimal type. This decoder 5 has eight inputs and 16 outputs. The 16 outputs are, in

turn, applied to potentiometers 4 to 19. Resistors 20 to 35 are connected in series with the sliding contacts of the potentiometers. A mixing amplifier 36 receives the signal outputs from the potentiometers, by way of the series-connected resistors.

The output of the amplifier 36 is applied to the winding of a potentiometer 37. It is the function of this .potentiometer 37 to control the total amplitude. The signal appearing at the movable contact of the potentiometer 37, is applied to an output amplifier 39, through a resistor 38. The amplifier receives another input in the form of a d-c voltage derived from. a potentiometer 40. The voltage from the potentiometer 40 is applied to the amplifier 39 through the resistor 41 connected in series with the movable contact of the potentiometer 40. Feedback voltage is applied to the amplifier 39 through the resistor 42. The output signal of the amplifier 39 is applied to a deflection coil 43, and the feedback voltage corresponds to the current through the deflection coil. A shunt resistor 44 is connected to the deflection coil 43. The frequency present at the deflection coil is 1/16 of the frequency of the astable multivibrator 1.

On the front panel of the device, shown in FIG. 2, the potentiometers 4 to 19 are represented as linear sliding potentiometers with sliding or movable contacts 45 to 60. The positions of the sliding parts in their sliding slots correspond to the image of the adjusted curve form.

On the front panel of the device, furthermore, there is provided the potentiometer 40 for the superposed d-c voltage, and the amplitude control potentiometer 37. A power supply switch 61 and a control lamp 62 are also present on the front panel. The device, in accordance with the present invention, is advantageously constructed when in the form of an electronic drawer unit.

What is claimed is:

1. Apparatus for the production of voltage functions adjustable to curve configurations, in particular for the production of preset deflection functions for the deflection of an electron beam in a machining unit operated by an electron beam comprising, in combination, means for generating a plurality of rectangular pulses of constant amplitude in periodic succession; potentiometers receiving said pulses in order and attenuating said pulses between proportions of 0 and percent, said potentiometers being linear sliding potentiometers; panel means for mounting said potentiometers, said potentiometers being adjustable through movable parts riding within parallel sliding slots, the positions of said sliding parts corresponding to the set curve configuration of the voltage function; and means for summing said attenuated pulses from said potentiometers for producing an output signal for a curve form corresponding to the settings of said potentiometers.

t i l l 

1. Apparatus for the production of voltage functions adjustable to curve configurations, in particular for the production of preset deflection functions for the deflection of an electron beam in a machining unit operated by an electron beam comprising, in combination, means for generating a plurality of rectangular pulses of constant amplitude in periodic succession; potentiometers receiving said pulses in order and attenuating said pulses between proportions of 0 and 100 percent, said potentiometers being linear sliding potentiometers; panel means for mounting said potentiometers, said potentiometers being adjustable through movable parts riding within parallel sliding slots, the positions of said sliding parts corresponding to the set curve configuration of the voltage function; and means for summing said attenuated pulses from said potentiometers for producing an output signal for a curve form corresponding to the settings of said potentiometers. 